The challenges of being married to a person with a mental illness or disorder are often made considerably worse during the divorce process, and an individual with a mental health challenge will see their symptoms worsen during divorce.
Many people with mental health concerns have additional barriers to achieving intimacy and have trouble consistently engaging in behaviors that support a marriage.
Studies report major depression and addictions as the top two mental health conditions that contribute to divorce. In addition, bipolar disorder seems to relate to divorce by virtue of how long and how severe the depressive episodes are, and the amount of life stress associated with a manic episode (for example: debt incurred or partner betrayed by cheating).
Anxiety is another mental health condition that can severely affect a relationship. Someone with chronic anxiety tends to seek a high amount of emotional support from a spouse, and I have seen an increase in impatience from the non-anxious spouse. Some anxious clients also seem to experience an increase in their personal stress levels just by being in a relationship, and some decide to end the relationship themselves to relieve that tension.